Typical piston/cylinder assemblies include a cylindrical housing and cylinder heads for enclosing a piston therein. A poston rod typically extends axially from the piston for engagement with a workpiece. Where substantially large pressures are required to move the piston, the cylinder, cylinder heads, piston, and piston rod (s) are accordingly made thicker and heavier, thus increasing the size and weight of the assembly. Such increased size and weight are detrimental in cases wherein space is critical.
In some cases, where small strokes of the piston can be tolerated in an effort to decrease the size and weight of the piston assembly, metallic pistons have been replaced by lightweight diaphragms. However, diaphragms are susceptible of being punctured. Evan a small puncture is detrimental since even small leakages cannot be tolerated in such assemblies.